JCLOUDS-155: Making header handling in OpenStack case-insensitive

Submitted by Rodney Beede
JCLOUDS-220. Adding projectId to a bunch of CloudStack API options
JCLOUDS-221. Add availabilityZone to spot price history.
Remove async from softlayer
When creating a server, allow attaching server to custom network
https://issues.apache.org/jira/browse/JCLOUDS-202